METHOD FOR SEPARATING NOBLE METAL FROM ALKALINE AQUEOUS CYANIDE SOLUTION AND ION-CHANGING RESIN WITH GUANIDINE FUNCTIONALITY Russian patent published in 1995 - IPC

FIELD: separation of noble metals. SUBSTANCE: method involves separating noble metals, such as gold and silver, by providing contacting with certain guanidine reactants, which do not only extract noble metal but also provide advantages, such as selectivity with respect to gold as compared to other metals. Reactants are tetra-and penta (hydrocarbon) substituted nonresinous guanidine reactants and tri-and tetra (hydrocarbon) substituted resinous guanidine reactants. EFFECT: increased efficiency in separating noble metals. 15 cl, 4 tbl